Method for making balloon catheter

ABSTRACT

The present invention relates to a method for making a silicon balloon catheter in which a first tube having its outer diameter slightly smaller than that of a desired catheter is formed by an extruding method, mold lubricant is coated at a portion of a balloon injection opening, a thin film type second tube is formed at the coated outer surface of the first tube by a second extruding, and then the catheter is vulcanized and cut. As a result, when liquid is injected to an expansion tube, the second tube is separated from the first tube, thereby performing a function as a balloon. The method for making a balloon catheter using silicon rubber includes the steps of: forming a first tube by extruding firstly, the tube having its outer diameter slightly smaller than that of a desired catheter, then vulcanizing and cutting the first tube; punching two balloon injection openings having small diameter at a portion for expanding into balloon in the first tube after inserting a support rod into a discharge tube path; coating mold lubricant at a portion of the balloon injection opening; connecting the first tubes coated the mold lubricant by using a connection unit after removing the support rod, and thereafter forming a second tube at the coated outside surface of the first tube by extruding secondly, performing a vulcanizing process and cutting again; forming a tip at the tip portion of the first and second tubes; and punching a urine discharge opening at the first tube.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method for making a siliconballoon catheter, and more particularly, to a method for making asilicon balloon catheter in which a first tube having its outer diameterslightly smaller than that of a desired catheter is formed by anextruding method, mold lubricant is coated at a portion of a ballooninjection opening, a thin film type second tube is formed at the coatedouter surface of the first tube by a second extruding, and then thecatheter is vulcanized and cut. As a result, when liquid is injected toan expansion tube, the second tube is separated from the first tube,thereby performing a function as a balloon.

[0003] 2. Description of the Related Art

[0004] In general, a catheter made of silicon is a thin and long tubebeing inserted into the human body in order to draw blood or injectmedicine. For example, it is used a urine path tube, that is, it isinserted to bladder through urethra in order to make urine filled withinthe bladder discharge.

[0005]FIG. 1 is a cross-sectional view illustrating a balloon catheterin accordance with a conventional art. FIG. 2 is a block diagramillustrating a manufacturing method of a balloon catheter in accordancewith a conventional art.

[0006] In a construction of the conventional art (referring to FIG. 1),a tube 13 has a partition 19 between a discharge tube path 12 fordischarging urine through a urine discharge opening 17 and an expansiontube 14 for expanding a balloon. A balloon layer 16 is adhered to anoutside of the tube 13 by an adhesive 18. Also, the conventionalcatheter has a balloon injection opening 15 for making the expansiontube 14 and the inside 16 a of the balloon communicate.

[0007] In order to manufacture the catheter as constructed above,firstly, the tube 13 is extruded in order to provide the discharge tubepath 12 and an expansion tube 14 in step S1, thereafter vulcanized instep S2 and cut with a predetermined length in step S3.

[0008] Next, the balloon injection opening 15 and the urine dischargeopening 17 are punched in step S4 and then a tip portion 11 is formed instep S5. Thereafter, the balloon 16 molded in a separate process, i.e.,the step S6, is adhered by adhesive in step S7 and then over-coated instep S8.

[0009] However, in the catheter as described above, there are severaldisadvantages that since it is manufactured by an adhesion of a balloonmolded by a separate process, the diameter of the balloon portion becomethicker relatively in comparison with an another portion of thecatheter. As a result, the portion caused a patient to feel a very bigpain in the surgical operation and also sometimes there is a serioussituation that the adhesive portion is apt to be separated.

[0010] Also, U.S. Pat. No. 5,137,671 disclose an another conventionalcatheter manufacturing method.

[0011] In the explanation of the manufacturing method with reference todrawings, as shown in FIG. 3a, there is provided a tube 100. The tube100 includes a first tube 120 (a tube having a big diameter) and asecond tube 140 (a capillary tube having a small diameter).

[0012] When the tube 100 as described above is provided, as shown inFIG. 3b, a first opening 160 communicating the second tube 140 at theouter surface of the balloon expansion unit is punched. Thereafter, apolymerization type filling material 180 like silicon rubber is filledwithin the second tube 140 from an end (a lower end) of the tube 100 tothe first opening 160. Also, a tip 200 is attached to a lower end of thetube 100 and then the ends of the first and second tubes 120 and 140 areclosed.

[0013] Next, the tube 100 is dipped into mold lubricant liquid (soapywater or Vaseline liquid etc.) from its end to the balloon expansionunit, especially until the line of A-A of the tube 100 and thensolidified. Thereafter, the tube 100 is coated by a mold lubricant 300until the balloon expansion unit of the outer surface of the tube. Atthe same time, the mold lubricant 300 is filled at the first opening 160and a portion of the second tube 140, so that the tube is formed asshown in FIG. 3c. That is, the mold lubricant is filled within thesecond tube from the line of A-A of the balloon expansion unit to thefirst opening and coated at the outer surface of the tube between thelines of A-A and BB.

[0014] Thereafter, as shown in FIG. 3d, the tube 100 is processed bysurface active agent until before (the line of B-B) the balloonexpansion unit, dipped into predetermined water or hot water on severaltimes and then the mold lubricant coated except for the balloonexpansion unit is removed. Thereafter, as shown in FIG. 3e, many foldslayers, that is two folds in the FIG. 3e, are coated at the entire outersurface of the tube 100, thereby forming an overcoat layer 400.

[0015] Next, the filled and coated mold lubricant of the balloonexpansion unit is removed through the second tube 140 of the tube,thereby forming a space portion 440 for expanding the balloon.

[0016] However, in case of the balloon catheter manufactured by theabove processes, after dipping the tube into the mold lubricant liquid,the mold lubricant coated at a portion (between the end and the line ofB-B) except for the balloon expansion opening is removed. At this time,in the dipping process of the tube in water by several times, wastewateris increased, thereby occurring environmental pollution.

[0017] Also, there is a disadvantage that when the mold lubricant didnot completely removed, after forming the space portion, pushingphenomenon is occurred, so that the surrounding overcoat layer isexfoliated and swelled together with the space portion.

[0018] Also, the conventional catheter manufacturing method does notsolve the problem that the diameter of the balloon portion is thickerthan that of the other portion.

[0019] As an example of an another conventional art, a silicon rubbercatheter is disclosed in Japanese Patent Registration No. 3015310registered on Jun. 21, 1995.

[0020] According to the above conventional art, a balloon is installedas one body in order to coat the surface of the catheter body. Acatheter body having a discharge tube path formed by an extrudingprocess through silicon rubber material and a drain at the outside ofthe tube wall is vulcanized and then mold lubricant is coated to amolding end (a portion for forming a balloon) of an insertion fixingportion. Thereafter, a wall (a balloon) is stacked at the outer surfaceof the tube wall of the catheter body and vulcanized again and so a tipportion is formed. At this time, the wall and the tube wall of thecatheter is formed at the same surface, so that the resistance by thestep portion of the wall surface is broken off and at the same time,transformation of the wall surface is prevented.

[0021] However, practically, it is impossible to manufacture theexpansion tube of a continuous drain type for expanding/contracting theballoon according to the above conventional art.

[0022] Because the silicon rubber layer coated in second extruding makesthe drain to be depressed. If the silicon rubber layer is coated withthinness, since the adhesion force is not sufficient, a phenomenon thata portion except for the balloon portion is exfoliated is occurred.

SUMMARY OF THE INVENTION

[0023] To solve the above problems, it is an object of the presentinvention to provide a method for making a silicon balloon catheter inwhich since a step portion of the balloon portion is removed, a pain tothe patient in surgical operation is relieved. Also, a portion exceptfor the balloon portion is prevented from separating, at the same timeproductivity can be enhanced and the manufacturing cost can be reduced.

[0024] To achieve the above object, there is provided a method formaking a balloon catheter using silicon rubber A method for making aballoon catheter using silicon rubber comprising the steps of: forming afirst tube by extruding firstly, the tube having its outer diameterslightly smaller than that of a desired catheter, then vulcanizing andcutting the first tube; punching two balloon injection openings havingsmall diameter at a portion for expanding into balloon in the first tubeafter inserting a support rod into a discharge tube path; coating moldlubricant at a portion of the balloon injection opening; connecting thefirst tubes coated the mold lubricant by using a connection unit afterremoving the support rod, and thereafter forming a second tube at thecoated outside surface of the first tube by extruding secondly,performing a vulcanizing process and cutting again; forming a tip at thetip portion of the first and second tubes; and punching a urinedischarge opening at the first tube.

[0025] An embodiment of the present invention is disclosed in order tomake a silicon rubber catheter having no a step portion economically, inwhich when air is injected to an expansion tube, a portion coated bymold lubricant between the first and second tubes is separated andexpanded, thereby performing a function as a balloon.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription when taken in conjunction with the accompanying drawings, inwhich:

[0027]FIG. 1 is a view illustrating a construction of balloon catheterin accordance with the conventional art;

[0028]FIG. 2 is a block diagram illustrating a method for making aballoon catheter in accordance with the conventional art;

[0029]FIGS. 3a to 3 f are longitudinal cross-sectional viewsillustrating processes of a balloon catheter manufacturing method inaccordance with the conventional art;

[0030]FIGS. 4a to 4 i are longitudinal cross-sectional viewsillustrating processes of a balloon catheter manufacturing method inaccordance with the present invention;

[0031]FIG. 5 is a cross-sectional view illustrating a construction of aballoon catheter manufactured in accordance with the present invention;and

[0032]FIG. 6 is a block diagram illustrating a method for making aballoon catheter in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0033]FIGS. 4a to 4 i are longitudinal cross-sectional viewsillustrating processes of a balloon catheter manufacturing method inaccordance with the present invention. FIG. 5 is a cross-sectional viewillustrating the construction of a balloon catheter manufactured inaccordance with the present invention. FIG. 6 is a block diagramillustrating a method for making a balloon catheter in accordance withthe present invention.

[0034] Firstly, as shown in FIG. 4a, in a preferred embodiment of thepresent invention, a first tube is formed by an extruding method. Theouter diameter of the first tube is slightly smaller than the diameterof a desired balloon catheter. The first tube 20 provides with adischarge tube path 22 and an expansion tube 24 (step of S11 of FIG. 6).Thereafter, the first tube is vulcanized and as a result it haselasticity and thereafter, it is cut with a predetermined length in thestep of S12.

[0035] At this time, the cross-section of the first tube 20 has the formlike FIG. 4c. FIG. 4b shows a cross-section shape of the conventionalart.

[0036] As shown in the above drawings, the form of the cross-section ofthe tube 13 of the conventional art is slightly similar to that of thefirst tube 20 of the present invention. However, the thickness, tb andTh, of the first tube 20 are significantly thinner than that, ta and Taof the conventional tube 13. This is for securing facilities in workingwhen punching the balloon injection opening to be explained hereinafter,enhancing the rate of success, and securing a urination discharge tubepath as large as it can.

[0037] Also, at the outside of the first tube 20 can form thinly asshown in FIG. 4c, considering the coated thickness again in secondextruding process. In general, the thickness ta between the outsidesurface of the conventional tube 13 and the expansion tube 14 is 0.5 mmand the thickness Ta of circumference is 0.9 mm. Whereas, it is desirousthat the thickness tb between the outside surface of the first tube 20of the present invention and the expansion tube 24 is 0.3 mm and thethickness Th of circumference of the first tube 20 is 0.7 mm.

[0038] Also, a horizontal type extruding machine and a vulcanizingmachine are used in the conventional tube extruding S1 and vulcanizationS2 processes. Whereas, it is desirous that a vertical type extrudingmachine and a vulcanizing machine are used in the first tube extrudingS11 and vulcanization S12 processes. When the horizontal type extrudingmachine and the vulcanizing machine are used, some contact traces areremained to the surface of the tube, so that the traces are remained asscars at the balloon portion in next time, thereby generatingeccentricity in balloon expansion or breaking the balloon.

[0039] Next, as shown in FIG. 4d, a balloon injection opening 23 ispunched to the first tube 20 in step 13. At this time, a support rod 29(referring to FIG. 4e) is inserted to the discharge tube path 22, sothat the rubber tube is maintained in straight line, thereby capable ofperforming work easily. When forming the balloon injection opening 23,in the conventional art, an opening having a big diameter (about thediameter of 1.5 mm) is punched at the center portion (15 of FIG. 1).Whereas, in an embodiment of the present invention, two openings (aboutthe diameter of 0.5 mm) are punched at an edge portion of the balloonformation portion, that is, apart from about 2˜3 mm from the boundaryline. The two openings are as small as it can and smaller than that ofthe opening of the convention art.

[0040] Here, the opening of the balloon injection opening 23 is formedin small, because, if the opening is big, the balloon formation layer30′ is depressed into the opening in the second extruding process (S16of FIG. 6) and the thickness of the balloon become to be differed. As aresult, when expanding the balloon, it does not expand symmetrically andit may become a cause of breaking.

[0041] Next, as shown in FIG. 4f, mold lubricant 28 is coated to anoutside portion, that is, a portion for forming the balloon, of thefirst tube 20 in step S14. In the mold lubricant coating process, sincethe mold lubricant must be coated only to the portion punched theballoon injection opening 23 in the first tube 20, turning thecircumference of the outer surface of the first tube 20 by a round.Also, the coating boundary surface must be formed as a straight line, soit must take note of the work.

[0042] At this time, the used mold lubricant 28 is liquid type soapcapable of purchasing easily in the street. Also, the mold lubricant 28is used material by mixing Teflon liquid with transparent ink and it isdesirous to add water or alcohol for fitting the viscosity.

[0043] As described above, the mold lubricant having the fittedviscosity is deposited in a sponge etc. and then coated only to theportion punched the balloon injection opening 23, turning the first tubeby a round uniformly. After coating the mold lubricant, it is exposed tohot wind in weak with about 60˜70° C. in step S14.

[0044] After the mold lubricant is dried sufficiently, the support rod29 inserted to the injection tube path is removed (referring to FIG.4f). Thereafter, the first tubes are connected with the same directionby a connecting unit 39 (referring to FIG. 4g) lengthwise in step S15,so that when extruding the second tube, a continuous working ispossible.

[0045] Next, as shown in FIG. 4h, a second tube 30 is formed at theoutside of the first tube 20 through the second extruding process byusing a vertical type extruder in step S16 and then vulcanized by usinga vulcanizing machine in step S17. At this time, the thickness of thesecond tube must be maintained uniformly and also it is required thatthe coating portion of the mold lubricant does not discolor or thecharacteristic of the mold lubricant does not deteriorate.

[0046] In the tube completed the vulcanizing process, the portionconnected before the second extruding is cut again in step S17 and thenthe connection units 39 are removed, a tip 40 is formed in step S18, asshown in FIG. 41, and then a urine discharge opening 26 is punched.

[0047] The product completed through the above processes is shown inFIG. 5, the balloon formation portion 30′ is expanded symmetrically witheach other when air is injected through the expansion tube 24, so thatan expansion tube 32 is formed.

[0048] On the other hand, in the conventional balloon manufacturingprocesses, a worker is required in the processes S1˜S4 of tubeextruding, vulcanizing, cutting and punching in the balloon injectionopening/a urine discharge opening, respectively. Five and three workersare required in the tip formation process in step S5 and balloon moldingprocess in step S6, respectively. Also, eight and five workers arerequired in the balloon adhesion process in step S7 and overcoat processin step S8, respectively. As a result, many workers are required and soit caused the manufacturing cost to rise.

[0049] Whereas, in manufacturing the balloon catheter of the presentinvention, nine workers all are sufficient. That is, a worker isrequired in the first tube extruding and vulcanizing/cutting processesS11 and S12. Two workers are required in the punching process of thesupport rod insertion and the balloon injection opening S13. A worker isrequired in the coating process S14 of mold lubricant. Two workers arerequired in the process S15 of the support rod removal and the firsttube connection. A worker is required in the processes of the secondtube extruding S16 and the vulcanizing/cutting S17. A worker is requiredin the processes S18 and S19 of tip formation and punching a urinedischarge opening, respectively. Therefore, according to the presentinvention, there are several advantages that the workers and the costare reduced. According to the embodiment of the present invention asdescribed above, there is provided to a method for making a siliconballoon catheter in which a first tube having its outer diameterslightly smaller than that of a desired catheter is formed by anextruding method, mold lubricant is coated at a portion of a ballooninjection opening, a thin film type second tube is formed at the coatedouter surface of the first tube by a second extruding, and then thecatheter is vulcanized and cut. As a result, when liquid is injected toan expansion tube, the second tube is separated from the first tube,thereby performing a function as a balloon. Also, since a step portionof the balloon portion is removed, a pain to the patient in surgicaloperation is relieved. A portion except for the balloon portion isprevented from separating, at the same time productivity can be enhancedand the manufacturing cost can be reduced.

[0050] While the invention has been shown and described with referenceto certain preferred embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims.

What is claimed is:
 1. A method for making a balloon catheter usingsilicon rubber comprising the steps of: forming a first tube byextruding firstly, the tube having its outer diameter slightly smallerthan that of a desired catheter, then vulcanizing and cutting the firsttube; punching two balloon injection openings having small diameter at aportion for expanding into balloon in the first tube after inserting asupport rod into a discharge tube path; coating mold lubricant at aportion of the balloon injection opening; connecting the first tubescoated the mold lubricant by using a connection unit after removing thesupport rod, and thereafter forming a second tube at the coated outsidesurface of the first tube by extruding secondly, performing avulcanizing process and cutting again; forming a tip at the tip portionof the first and second tubes; and punching a urine discharge opening atthe first tube.